package com.spring.springboot.util;

import com.spring.springboot.util.vo.Gps;
import org.jetbrains.annotations.NotNull;
import org.springframework.stereotype.Component;

/**
 * @author 15625
 * @date 2021-04-10 11:18
 * <p>
 * 地球坐标系(WGS84),
 * 火星坐标系(GCJ02),
 * 百度坐标系(BD09)
 */
@Component
public class PositionUtils {

    /**
     * PositionUtil：各地图API坐标系统比较与转换;
     * WGS84坐标系：即地球坐标系，国际上通用的坐标系。设备一般包含GPS芯片或者北斗芯片获取的经纬度为WGS84地理坐标系,谷歌地图采用的是WGS84地理坐标系（中国范围除外）;
     * GCJ02坐标系：即火星坐标系，是由中国国家测绘局制订的地理信息系统的坐标系统。由WGS84坐标系经加密后的坐标系。谷歌中国地图和搜搜中国地图采用的是GCJ02地理坐标系;
     * BD09坐标系：即百度坐标系，GCJ02坐标系经加密后的坐标系;
     * 搜狗坐标系、图吧坐标系等，估计也是在GCJ02基础上加密而成的。
     */

    public static final double pi = 3.1415926535897932384626;

    public static final double a = 6378245.0;

    public static final double ee = 0.00669342162296594323;

    /**
     * 地球坐标系 (WGS84) to 火星坐标系 (GCJ-02) World Geodetic System ==> Mars Geodetic System
     *
     * @param lat 纬度
     * @param lon 精度
     * @return Gps
     */
    public static Gps gps84_To_Gcj02(double lat, double lon) {
        if (outOfChina(lat, lon)) {
            return null;
        }
        return getGps(lat, lon);
    }

    /**
     * 火星坐标系 (GCJ-02) to 地球坐标系 (WGS84)
     *
     * @param lon
     * @param lat
     * @return Gps
     */
    public static Gps gcj_To_Gps84(double lat, double lon) {
        Gps gps = transform(lat, lon);
        double longitude = lon * 2 - gps.getLongitude();
        double latitude = lat * 2 - gps.getLatitude();
        return new Gps(latitude, longitude);
    }

    /**
     * 火星坐标系 (GCJ-02) 与百度坐标系 (BD-09) 的转换算法
     * 将 GCJ-02 坐标转换成 BD-09 坐标
     *
     * @param gg_lat 纬度
     * @param gg_lon 经度
     * @return Gps
     */
    public static Gps gcj02_To_Bd09(double gg_lat, double gg_lon) {
        double z = Math.sqrt(gg_lon * gg_lon + gg_lat * gg_lat) + 0.00002 * Math.sin(gg_lat * pi);
        double theta = Math.atan2(gg_lat, gg_lon) + 0.000003 * Math.cos(gg_lon * pi);
        double bd_lon = z * Math.cos(theta) + 0.0065;
        double bd_lat = z * Math.sin(theta) + 0.006;
        return new Gps(bd_lat, bd_lon);
    }

    /**
     * * 火星坐标系 (GCJ-02) 与百度坐标系 (BD-09) 的转换算法
     * 将 BD-09 坐标转换成GCJ-02 坐标
     *
     * @param bd_lat
     * @param bd_lon
     * @return Gps
     */
    public static Gps bd09_To_Gcj02(double bd_lat, double bd_lon) {
        double x = bd_lon - 0.0065;
        double y = bd_lat - 0.006;
        double z = Math.sqrt(x * x + y * y) - 0.00002 * Math.sin(y * pi);
        double theta = Math.atan2(y, x) - 0.000003 * Math.cos(x * pi);
        double gg_lon = z * Math.cos(theta);
        double gg_lat = z * Math.sin(theta);
        return new Gps(gg_lat, gg_lon);
    }

    /**
     * 百度坐标系 (BD-09) 与 地球坐标系 (WGS84) 坐标系转换算法
     * 将 (BD-09) 坐标转换成 (WGS84) 坐标
     *
     * @param bd_lat 百度纬度
     * @param bd_lon 百度经度
     * @return Gps
     */
    public static Gps bd09_To_Gps84(double bd_lat, double bd_lon) {
        Gps gcj02 = PositionUtils.bd09_To_Gcj02(bd_lat, bd_lon);
        return PositionUtils.gcj_To_Gps84(gcj02.getLatitude(), gcj02.getLongitude());
    }

    public static boolean outOfChina(double lat, double lon) {
        if (lon < 72.004 || lon > 137.8347) {
            return true;
        }
        return lat < 0.8293 || lat > 55.8271;
    }

    public static Gps transform(double lat, double lon) {
        if (outOfChina(lat, lon)) {
            return new Gps(lat, lon);
        }
        return getGps(lat, lon);
    }

    public static double transformLat(double x, double y) {
        double ret = -100.0 + 2.0 * x + 3.0 * y + 0.2 * y * y + 0.1 * x * y + 0.2 * Math.sqrt(Math.abs(x));
        ret = getRet(x, ret, y * pi, y / 3.0);
        ret += (160.0 * Math.sin(y / 12.0 * pi) + 320 * Math.sin(y * pi / 30.0)) * 2.0 / 3.0;
        return ret;
    }

    public static double transformLon(double x, double y) {
        double ret = 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y + 0.1 * Math.sqrt(Math.abs(x));
        ret = getRet(x, ret, x * pi, x / 3.0);
        ret += (150.0 * Math.sin(x / 12.0 * pi) + 300.0 * Math.sin(x / 30.0 * pi)) * 2.0 / 3.0;
        return ret;
    }

    private static double getRet(double x, double ret, double v, double v2) {
        ret += (20.0 * Math.sin(6.0 * x * pi) + 20.0 * Math.sin(2.0 * x * pi)) * 2.0 / 3.0;
        ret += (20.0 * Math.sin(v) + 40.0 * Math.sin(v2 * pi)) * 2.0 / 3.0;
        return ret;
    }

    @NotNull
    private static Gps getGps(double lat, double lon) {
        double dLat = transformLat(lon - 105.0, lat - 35.0);
        double dLon = transformLon(lon - 105.0, lat - 35.0);
        double radLat = lat / 180.0 * pi;
        double magic = Math.sin(radLat);
        magic = 1 - ee * magic * magic;
        double sqrtMagic = Math.sqrt(magic);
        dLat = (dLat * 180.0) / ((a * (1 - ee)) / (magic * sqrtMagic) * pi);
        dLon = (dLon * 180.0) / (a / sqrtMagic * Math.cos(radLat) * pi);
        double mgLat = lat + dLat;
        double mgLon = lon + dLon;
        return new Gps(mgLat, mgLon);
    }
}
